A ground-based navigation system, which guides the running of a vehicle, navigates the vehicle using signals from a GPS satellite. When the signals from the GPS satellite are blocked or reflected by a high-rise building to prevent a sufficient receipt of the signals, an accurate guide of the running is impossible.
To prevent this, it has been conventionally carried out to use, when signals from a GPS satellite cannot be received sufficiently, some kind of methods to perform an estimate navigation, thereby preventing the navigation from being interrupted. However, many of these methods use sensor information obtained from a yaw rate sensor or an acceleration sensor. Thus, an increased cost has been caused.
To solve this, an estimate navigation not using an additional sensor has been suggested (e.g., see Patent Literature 1). The method disclosed in Patent Literature 1 calculates the accurate dynamic loaded radii of the respective tires attached to the vehicle to perform geometrically an estimate navigation based on the calculated values of the dynamic loaded radii.
Citation List
Patent Literature
    Patent Literature 1: Published Japanese translation of a PCT application No. 2000-514195